What are the indexes in a database used for?

Indexes in a database are needed to speed up search and data retrieval. They work as pointers to the table rows, allowing the DBMS to quickly find the required records without scanning the entire table (full table scan). This is especially important when working with large volumes of data and complex queries.

Indexes can be created on one or multiple columns and come in different types (e.g., B-tree, hash). However, indexes occupy additional space and slow down insert, update, and delete operations, as they need to be maintained in an up-to-date state.